VECTOR CONTROLLED RELUCTANCE SYNCHRONOUS MOTOR DRIVES WITH PRESCRIBED

VECTOR CONTROLLED RELUCTANCE SYNCHRONOUS MOTOR DRIVES WITH PRESCRIBED CLOSED-LOOP SPEED DYNAMICS

Model of Reluctance Synchronous Motor Non-linear differential equations formulated in rotorfixed d, q co-ordinate system describe the reluctance synchronous motor and form the basis of the control system development.

Control Structure for Reluctance Synchronous Motor

Master Control Law Dynamic torque equation Vector control condition for maximum torque a) per unit stator current Demanded dynamic behavior b) for a given stator flux Linearising function a) b)

SET OF OBSERVERS FOR STATE ESTIMATION AND FILTERING

Pseudo-Sliding Mode Observer for Rotor Speed a) definition of error Motor equations Model system

Angular velocity extractor Error system Sliding-Mode Observer Equivalent variables Condition for Sliding Motion Pseudo-SMC Observer Estimate of rotor speed

The Filtering Observer Filtered values of and are produced by the observer based on Kalman filter Load torque is modeled as a state variable VJ where design of: needs adjustment of the one parameter only or as two different poles: Electrical torque of SRM is treated as an external model input

Original control structure of speed controlled RSM demanded rotor speed demanded d_q stator currents Id dem wd Master Control Law Tw wr Slave control law d_q a_b & a, b, c transf Iq dem Switching table s Id I q Ud Uq Filtering observer * r Id Iq a_b & d_q transf. Reluctance Synchronous Motor I 1 I 2 - I 3 vd_eq Rotor flux calculator Yd w Ud Uq external load torque GL demanded threephase voltages U 1 Power U 2 electronic U 3 drive circuit Udc Yq Y* Sliding-mode observer vq_eq Angular velocity extractor rotor position sensor q Measured variables: rotor position, stator current, DC circuit voltage * r w

Inner & Middle Loop (real system) MRAC outer loop correction loop Model TF Reference Model (of closed-loop system) Parameter mismatch increases a correction Mason’s rule

Simulation results a 1) id=const without MRAC a) id, iq = f(t) d) wid, west = f(t) b) Yd, Yq = f(t) e) GL, GLest = f(t) c) Ld = f(t) f) wid, wr = f(t)

Simulation results a 2) id=const with MRAC a) id, iq = f(t) d) wid, west = f(t) b) Yd, Yq = f(t) e) GL, GLest = f(t) c) Ld = f(t) f) wid, wr = f(t)

Simulation results (without MRAC) b 1) dq-current angle control a) id, iq = f(t) d) wid, west = f(t) b) Yd, Yq = f(t) e) GL, GLest = f(t) c) Ld = f(t) f) wid, wr = f(t)

Simulation results (with MRAC) b 2) dq-current angle control a) id, iq = f(t) d) wid, west = f(t) b) Yd, Yq = f(t) e) GL, GLest = f(t) c) Ld = f(t) f) wid, wr = f(t)

Effect of MRAC on Various Types of Prescribed Dynamics a) constant torque b) first order dyn. c) second ord. dyn.

Conclusions and Recommendations n n The simulation results of the proposed new control method for electric drives employing SRM show a good agreement with theoretical predictions. The only departure of the system performance from the ideal is the transient influence of the external load torque on the rotor speed. This effect is substantially reduced if MRAC outer loop is applied. It is highly desirable to employ suggested control strategy experimentally.